GPS-Based Target Tracking System, Method and Dome Camera

ABSTRACT

Disclosed are GPS-based target tracking system, method and dome camera. The system comprises: a first camera and a second camera. The first camera obtains GPS coordinate of a target during the tracking of the target and sends the GPS coordinates to the second camera. The second camera adjusts a shooting angle of the second camera according to the GPS coordinates, and tracks the target after detecting the target in a second monitoring image shot by the second camera. Therefore, in the scheme, if the target moves out of the monitoring range of the first camera, the second camera continues to track the target, namely the tracking range of the target is expanded through linkage of the plurality of cameras.

The present application claims the priority to a Chinese patentapplication No. 201811485189.2, filed with the China NationalIntellectual Property Administration on Dec. 6, 2018 and entitled“GPS-based target tracking system, method and dome camera”, which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The application relates to the technical field of security, inparticular to a GPS-based target tracking system, method and domecamera.

BACKGROUND

In some scenes, monitoring targets such as vehicles and people can betracked through monitoring images shot by cameras. The technical schememay comprise: detecting a to-be-tracked monitoring target in the N-thframe image, determining positions of the monitoring target in the(N+1)-th frame image and subsequent images through a target trackingalgorithm, and converting the positions into a Global Positioning System(GPS) coordinates. As such, GPS coordinates of the monitoring target canbe continuously acquired, and thus the monitoring target can be tracked.

However, the monitoring range of a camera is limited. In above solution,once the monitoring target moves out of the monitoring range of thecamera, the tracking of the monitoring target is ceased. Therefore, thesolution has a small tracking range for the monitoring target.

SUMMARY

Embodiments of the present application provide a GPS-based targettracking system, method and dome camera, so as to improve the trackingrange.

An embodiment of the present application provides a GPS-based targettracking system, comprising: a first camera and a second camera;

the first camera is configured for determining a to-be-tracked target ina first monitoring image shot by the first camera, tracking theto-be-tracked target, obtaining GPS coordinates of the to-be-trackedtarget during the tracking, and sending the GPS coordinates of theto-be-tracked target to the second camera; and

the second camera is configured for adjusting a shooting angle accordingto received GPS coordinates of the to-be-tracked target, and trackingthe to-be-tracked target after detecting the to-be-tracked target in asecond monitoring image shot by the second camera.

In one embodiment, the first camera is configured for: converting imagecoordinates of the to-be-tracked target in the first monitoring imageinto the GPS coordinates of the to-be-tracked target; or

converting PT coordinates of the first camera at the time of capturingthe to-be-tracked target into the GPS coordinates of the to-be-trackedtarget.

In one embodiment, the first camera is configured for:

obtaining the PT coordinates to capture the to-be-tracked target, andtaking the P coordinate of the PT coordinates as a first P coordinateand taking the T coordinate of the PT coordinates as a first Tcoordinate;

determining a horizontal angle between the to-be-tracked target and aspecified direction based on the first P coordinate;

calculating a horizontal distance between the to-be-tracked target andthe first camera based on the first T coordinate and the height of thefirst camera;

calculating, according to the horizontal angle and the horizontaldistance, a longitudinal distance and a latitudinal distance between theto-be-tracked target and the first camera through trigonometricfunctions; and

calculating the GPS coordinates of the to-be-tracked target based on thelongitude and latitude of the first camera, and the longitudinaldistance and latitudinal distance.

In one embodiment, the first camera is configured for:

predicting a camera by which the to-be-tracked target is to pass basedon the GPS coordinates of the to-be-tracked target obtained during thetracking, and taking the predicted camera as the second camera; andsending the GPS coordinates of the to-be-tracked target to the secondcamera.

In one embodiment, the second camera is a dome camera which isconfigured for:

determining PT coordinates of the dome camera at the time of capturingthe to-be-tracked target according to received GPS coordinates of theto-be-tracked target; and

adjusting a shooting angle of the dome camera based on the PTcoordinates.

In one embodiment, the dome camera is configured for:

calculating a longitudinal distance and a latitudinal distance betweenthe dome camera and the to-be-tracked target according to the GPScoordinates of the to-be-tracked target and the GPS coordinates of thedome camera;

calculating a horizontal distance between the to-be-tracked target andthe dome camera according to the longitudinal distance and latitudinaldistance;

calculating a horizontal angle between the to-be-tracked target and aspecified direction through trigonometric functions according to thelongitudinal distance and latitudinal distance;

determining the P coordinate of the dome camera according to thehorizontal angle; and

calculating the T coordinates of the dome camera according to thehorizontal distance and the height of the dome camera.

In one embodiment, the system further comprises: a server;

the server is configured for sending attribute information of theto-be-tracked target to the first camera;

the first camera is configured for determining, based on receivedattribute information, the to-be-tracked target in the first monitoringimage shot by the first camera; and sending the attribute information tothe second camera; and

the second camera is configured for detecting, based on the receivedattribute information, the to-be-tracked target in the second monitoringimage shot by the second camera.

In one embodiment, the server is further configured for:

predicting a camera by which the to-be-tracked target is to pass basedon a pre-acquired historical trajectory of the to-be-tracked target;sending the attribute information of the to-be-tracked target to thepredicted camera; or

sending the attribute information of the to-be-tracked target to camerasmanaged by the server; or

sending the attribute information of the to-be-tracked target to aspecified camera managed by the server;

wherein, each of the predicted camera, the cameras, and the specifiedcamera comprises the first camera.

In one embodiment, the first camera is further configured for:

sending the GPS coordinates of the to-be-tracked target obtained duringthe tracking of the to-be-tracked target to the server; and

the server is further configured for:

predicting a camera by which the to-be-tracked target is to pass basedon the GPS coordinates of the to-be-tracked target and taking thepredicted camera as the second camera; and sending the GPS coordinatesof the to-be-tracked target to the second camera.

In one embodiment, the system further comprises: a third camera;

the second camera is further configured for obtaining GPS coordinates ofthe to-be-tracked target during the tracking of the to-be-trackedtarget, and sending the GPS coordinates of the to-be-tracked target tothe third camera;

the third camera is configured for adjusting a shooting angle accordingto received GPS coordinates of the to-be-tracked target, and trackingthe to-be-tracked target after detecting the to-be-tracked target in amonitoring image shot by the third camera.

An embodiment of the present application provides a GPS-based targettracking method, comprising:

determining a to-be-tracked target in a first monitoring image shot by afirst camera;

controlling the first camera to track the to-be-tracked target, and toobtain GPS coordinates of the to-be-tracked target during the tracking;

predicting a camera by which the to-be-tracked target is to pass basedon the GPS coordinates of the to-be-tracked target obtained during thetracking, and taking the predicted camera as a second camera; and

sending the GPS coordinates of the to-be-tracked target to the secondcamera so that the second camera tracks the to-be-tracked targetaccording to the GPS coordinates of the to-be-tracked target.

In one embodiment, determining a to-be-tracked target in a firstmonitoring image shot by a first camera comprises:

receiving attribute information of the to-be-tracked target sent by aserver or a camera other than the first camera; and

determining the to-be-tracked target in the first monitoring image basedon the attribute information;

after predicting a camera by which the to-be-tracked target is to passbased on the GPS coordinates of the to-be-tracked target obtained duringthe tracking, and taking the predicted camera as a second camera; themethod further comprises:

sending the attribute information to the second camera so that thesecond camera detects, based on the received attribute information, theto-be-tracked target in a second monitoring image shot by the secondcamera.

In one embodiment, obtaining GPS coordinates of the to-be-tracked targetduring the tracking comprises:

obtaining image coordinates of the to-be-tracked target in the firstmonitoring image during the tracking; converting the image coordinatesinto the GPS coordinates of the to-be-tracked target; or

obtaining PT coordinates of the first camera at the time of capturingthe to-be-tracked target during the tracking, and converting the PTcoordinates into the GPS coordinates of the to-be-tracked target.

In one embodiment, converting the PT coordinates into the GPScoordinates of the to-be-tracked target comprises:

obtaining the PT coordinates of the first camera at the time ofcapturing the to-be-tracked target, and taking the P coordinates of thePT coordinate as a first P coordinate and taking the T coordinate of thePT coordinates as a first T coordinate;

determining a horizontal angle between the to-be-tracked target and aspecified direction based on the first P coordinate;

calculating a horizontal distance between the to-be-tracked target andthe first camera based on the first T coordinate and the height of thefirst camera;

calculating, according to the horizontal angle and the horizontaldistance, a longitudinal distance and a latitudinal distance between theto-be-tracked target and the first camera through trigonometricfunctions; and

calculating the GPS coordinates of the to-be-tracked target based on thelongitude and latitude of the first camera, and the longitudinaldistance and latitudinal distance.

In one embodiment, controlling the first camera to track theto-be-tracked target comprises:

receiving attribute information of the to-be-tracked target sent by aserver or a camera other than the first camera;

determining PT coordinates of the first camera of capturing theto-be-tracked target according to received GPS coordinates of theto-be-tracked target; and

adjusting a shooting angle of the first camera based on the PTcoordinates.

In one embodiment, determining PT coordinates of the first camera at thetime of capturing the to-be-tracked target according to received GPScoordinates of the to-be-tracked target comprises:

calculating a longitudinal distance and a latitudinal distance betweenthe first camera and the to-be-tracked target according to the GPScoordinates of the to-be-tracked target and GPS coordinates of the firstcamera that captures the to-be-tracked target;

calculating a horizontal distance between the to-be-tracked target andthe first camera according to the longitudinal distance and latitudinaldistance;

calculating a horizontal angle between the to-be-tracked target and aspecified direction through trigonometric functions according to thelongitudinal distance and latitudinal distance;

determining the P coordinate of the first camera according to thehorizontal angle;

calculating the T coordinate of the first camera according to thehorizontal distance and the height of the first camera.

An embodiment of the application also provides a dome camera,comprising:

an image acquirer configured for shooting monitoring images;

a memory configured for storing a computer program; and

a processor configured for implementing any one of the above-mentionedGPS-based target tracking methods when executing the program stored inthe memory.

In the embodiment of the present application, a first camera obtains GPScoordinates of a target during the tracking of the target and sends theGPS coordinates to a second camera; and the second camera adjusts theshooting angle of the second camera according to the GPS coordinates,and tracks the target after detecting the target in a second monitoringimage shot by the second camera. Therefore, in the solution, if thetarget moves out of the monitoring range of the first camera, the secondcamera continues to track the target. In this way, the tracking range ofthe target is expanded through linkage of a plurality of cameras.

Obviously, it is not necessary for any product or method according tothe present application to achieve all of the above-described advantagesat the same time.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly explain the technical solution in theembodiment of this application and the prior art, the following willbriefly introduce the drawings that need to be used in the descriptionof the embodiments and the prior art. It is obvious that the drawingsdescribed below are only some embodiments of the present application.For those skilled in the art, other drawings can be obtained accordingto the drawings without paying creative work.

FIG. 1 is a schematic structural diagram of a first GPS-based targettracking system according to an embodiment of the present application;

FIG. 2 is a schematic structural diagram of a second GPS-based targettracking system according to an embodiment of the present application;

FIG. 3 is a schematic diagram of coordinate transformation in a verticaldirection in an embodiment of the present application;

FIG. 4 is a schematic diagram of coordinate transformation in ahorizontal direction in an embodiment of the present application;

FIG. 5 is a schematic flowchart of a GPS-based target tracking methodaccording to an embodiment of the present application;

FIG. 6 is a schematic structural diagram of a dome camera according toan embodiment of the present application.

DETAILED DESCRIPTION

The technical solutions in the embodiments of the present applicationwill be described clearly and completely with reference to the drawingsin the embodiments of the present application, and it is obvious thatthe described embodiments are only some embodiments of the presentapplication, and not all embodiments. All other embodiments obtained bya person of ordinary skill in the art based on the embodiments in thepresent application without making any creative effort belong to theprotection scope of the present application.

In order to solve the technical problem, the embodiment of theapplication provides a GPS-based target tracking system, method and domecamera. First, a detailed description will be given of the GPS-basedtarget tracking system according to the embodiments of the presentapplication.

FIG. 1 is a schematic structural diagram of a first GPS-based targettracking system according to an embodiment of the present application,comprising: a first camera and a second camera.

The first camera is configured for determining a to-be-tracked target ina first monitoring image shot by the first camera, controlling the firstcamera to track the to-be-tracked target, to obtain GPS coordinates ofthe to-be-tracked target during the tracking, and to send the GPScoordinates of the to-be-tracked target to the second camera.

The second camera is configured for adjusting a shooting angle of thesecond camera according to received GPS coordinates of the to-be-trackedtarget, and tracking the to-be-tracked target after detecting theto-be-tracked target in a second monitoring image shot by the secondcamera.

In the embodiment of the present application, the first camera obtainsthe GPS coordinates of the target during the tracking of the target andsends the GPS coordinates to the second camera; and the second cameraadjusts the shooting angle of the second camera according to the GPScoordinates, and tracks the target after detecting the target in asecond monitoring image shot by the second camera. Therefore, in thesolution, if the target moves out of the monitoring range of the firstcamera, the second camera continues to track the target. As such, thetracking range of the target is expanded through linkage of theplurality of cameras.

For ease of description, a camera that tracks a target first is referredto as a first camera, and a camera that tracks the target later isreferred to as a second camera; the monitoring image shot by the firstcamera is referred to as a first monitoring image, and the monitoringimage shot by the second camera is referred to as a second monitoringimage. The first camera and the second camera can be dome cameras.

For example, the target is a vehicle traveling on a road A. In thetraveling direction of the vehicle, the camera located behind the firstcamera is the second camera. For example, the order of the cameras maybe set in advance, and the first camera, the second camera, and the likemay be specified in the set order.

In one case, the first camera can determine the to-be-tracked target inthe first monitoring image shot by the first camera according to a userinstruction. For example, the first camera can present the firstmonitoring image shot by the first camera to the user, and the userclicks to select the to-be-tracked target in the first monitoring image.As another example, assuming that the to-be-tracked target is a vehicle,the user can input a license plate number of the to-be-tracked target,the first camera detects whether the license plate number exists in thefirst monitoring image shot by the first camera. If the license platenumber exists, the vehicle corresponding to the license plate number istaken as the to-be-tracked target.

In another case, referring to FIG. 2, the system comprises a server anda plurality of cameras, that is, a first camera, a second camera . . .an N-th camera, wherein N is a positive integer greater than 2. Theserver can extract the attribute information of the to-be-tracked targetand send the attribute information to the first camera, so that thefirst camera can determine the to-be-tracked target in the firstmonitoring image shot by the first camera based on the receivedattribute information, and send the attribute information to the secondcamera. The second camera can also detect the to-be-tracked target in asecond monitoring image shot by the second camera based on the receivedattribute information.

For example, the to-be-tracked target is a vehicle. The attributeinformation can be a license plate number. In another example, theto-be-tracked target is a person. The attribute information can be aface feature or a clothing feature. The present disclosure is notlimited in this aspect.

In this implementation, after extracting the attribute information ofthe to-be-tracked target, the server sends the attribute information toone camera. The camera then sends in turn the attribute information tothe next camera for tracking the to-be-tracked target. The next camerathen continues to send the attribute information to the next camera fortracking the to-be-tracked target, and so on. In this way, each cameracan detect the to-be-tracked target in the monitoring image shot by thecamera based on the received attribute information.

In one implementation, the server can predict a camera by which theto-be-tracked target is to pass based on a pre-acquired historicaltrajectory of the to-be-tracked target; and send the attributeinformation of the to-be-tracked target to the predicted camera.

For example, assuming that the to-be-tracked target is a vehicle A. Theserver acquires a historical trajectory of the vehicle A in advance,wherein the historical trajectory indicates that the movementtrajectories of the vehicle A are approximately the same from 8 am to 9am in the morning on weekdays, noted as trajectory X. Assuming that thecurrent time is five past 8 o 'clock in the morning on weekdays, theserver predicts that the next camera by which the vehicle A is to passis the camera 1 according to the track X, and sends the attributeinformation of the vehicle A to the camera 1. The camera 1 detects thevehicle A in the first monitoring image shot by the camera based on thereceived attribute information, and controls its pan tilt to track thevehicle A.

In another implementation, the server can also send attributeinformation of the to-be-tracked target to cameras managed by theserver. In this implementation, the server broadcasts the attributeinformation of the to-be-tracked target to cameras, and the camerasdetermine whether the to-be-tracked target enters the monitoring rangeof the camera.

Alternatively, the server can send the attribute information of theto-be-tracked target to a specified camera managed by the server.

For example, some cameras managed by the server, for example, a domecamera, can track a target; while other cameras with fixed positions andangles cannot track the target. Alternatively, some of the camerassupport the tracking function, while other cameras do not. In this case,the server can transmit the attribute information of the to-be-trackedtarget only to the cameras that can track the target, that is, theabove-described “a specified camera”.

Each of the predicted camera, cameras, and the specified cameracomprises the first camera. Of course, it is also possible to eachcomprise the above-mentioned second camera, which is all reasonable.

As described above, each camera can detect the to-be-tracked target in amonitoring image shot by the camera based on received attributeinformation. The following description is provided with reference to theexample in which a first camera and a second camera as examples.

The first camera can identify each candidate target in the firstmonitoring image and extract attribute information of each candidatetarget, match the attribute information of each candidate target withthe received attribute information, and determine the candidate targetas the to-be-tracked target if the matching degree is greater than afirst preset threshold.

Similarly, the second camera can identify each candidate target in thesecond monitoring image, extract attribute information of each candidatetarget, match the attribute information of each candidate target withthe received attribute information, and determine the candidate targetas the to-be-tracked target if the matching degree is greater than asecond preset threshold.

The first preset threshold and the second preset threshold can be thesame or different, and specific values are not limited.

In the embodiment of the application, the first camera obtains GPScoordinates of the to-be-tracked target during the tracking of theto-be-tracked target. In one case, the GPS coordinates of theto-be-tracked target can be continuously obtained during the tracking.For example, the GPS coordinates of the to-be-tracked target can beobtained once every second or every millisecond. The specific timeinterval is not limited.

There are various ways for the first camera to obtain GPS coordinates ofthe to-be-tracked target. In one implementation, the image coordinatesof the to-be-tracked target in the first monitoring image can beconverted into GPS coordinates of the to-be-tracked target.

For example, the mapping relationship between the image coordinatesystem and the GPS coordinate system can be defined in advance. Theimage coordinates of the to-be-tracked target are converted into the GPScoordinates according to the mapping relationship.

In another implementation, PT (Pan/Tilt, a pan tilt moves in a left orright/up or down way) coordinates of the first camera at the time ofcapturing the to-be-tracked target can be converted into the GPScoordinates of the to-be-tracked target. There are various ways toconvert PT coordinates into GPS coordinates, and a new conversion methodis proposed in the embodiment of the present application.

The conversion method can comprise: obtaining the PT coordinates at thetime of capturing the to-be-tracked target, and taking the P coordinateof the PT coordinates as a first P coordinate and taking the Tcoordinate of the PT coordinates as a first T coordinate; determining ahorizontal angle between the to-be-tracked target and a specifieddirection based on the first P coordinate; calculating a horizontaldistance between the to-be-tracked target and the first camera based onthe first T coordinate and the height of the first camera; calculating,according to the horizontal angle and the horizontal distance, alongitudinal distance and a latitudinal distance between theto-be-tracked target and the first camera through trigonometricfunctions; and calculating the GPS coordinates of the to-be-trackedtarget based on the longitude and latitude of the first camera, and thelongitudinal distance and latitudinal distance.

For ease of description, in the conversion method, the first camera isreferred to as a dome camera. The specified direction can be north,south, east, or west, and is not limited specifically.

In the conversion method, the P coordinate of the dome camera, when itpoints to the specified direction, can be obtained through an electroniccompass of the dome camera and is used as a second P coordinate; and thedifference between the first P coordinate and the second P coordinatecan be calculated and taken as the horizontal angle between theto-be-tracked target and the specified direction.

The P coordinate of the dome camera when pointing in the north, thesouth, the east, the west, and the like, can be acquired through theelectronic compass of the dome camera. For the purpose of distinction,this P coordinate is referred to as a second P coordinate. Thedifference between the first P coordinate and the second P coordinate isthe horizontal angle between the to-be-tracked target and the specifieddirection.

In the conversion method, the product of the tangent of the first Tcoordinate and the height of the dome camera can be calculated as thehorizontal distance between the to-be-tracked target and the domecamera. Referring to FIG. 3, tan T*h=L, h is the height of the domecamera, and L is the horizontal distance between the to-be-trackedtarget and the dome camera. The horizontal distance is the distancebetween the dome camera and the to-be-tracked target under the conditionthat the heights of the dome camera and the to-be-tracked target are thesame.

If the specified direction is north, the product of the sine of thehorizontal angle and the horizontal distance is calculated and taken asthe longitudinal distance between the to-be-tracked target and the domecamera; and the product of the cosine of the horizontal angle and thehorizontal distance is calculated and taken as the latitudinal distancebetween the to-be-tracked target and the dome camera.

Referring to FIG. 4, FIG. 4 is a top view of the dome camera, and doesnot show the height of the dome camera. As can be seen from FIG. 4,L*sin θ=L_(lon), L*cos θ=L_(lat), L is the horizontal distance obtainedby the above calculation, θ is the horizontal angle between theto-be-tracked target and the north direction, L_(lon) is thelongitudinal distance between the to-be-tracked target and the domecamera, and L_(lat) is the latitudinal distance between theto-be-tracked target and the dome camera.

If the specified direction is east, the product of the cosine of thehorizontal angle and the horizontal distance is calculated and taken asthe longitudinal distance between the to-be-tracked target and the domecamera; and the product of the sine of the horizontal angle and thehorizontal distance is calculated and taken as the latitudinal distancebetween the to-be-tracked target and the dome camera.

In this case, the horizontal angle between the to-be-tracked target andthe east direction is a in FIG. 4, L*sin α=L_(lon), L*cos α=L_(lat).

Alternatively, the specified direction is west or south, and thespecific calculation process is similar and is not described again.

The dome camera is usually provided with a GPS positioning devicethrough which GPS coordinates of the dome camera can be obtained. TheGPS coordinate comprises a longitude and a latitude. With the longitudeand latitude of the dome camera, and longitudinal and latitudinaldistances between the dome camera and the to-be-tracked target, thelongitude and latitude of the to-be-tracked target can be calculated,and the GPS coordinates of the to-be-tracked target is also obtained.

In one implementation, the first camera can predict a camera by whichthe to-be-tracked target is to pass as a second camera based on the GPScoordinates of the to-be-tracked target obtained during the tracking;and sending the GPS coordinates of the to-be-tracked target to thesecond camera.

The camera by which the to-be-tracked target is to pass can be a nextcamera by which the to-be-tracked target is to pass. It is assumed thatthe first camera is an N-th camera by which the to-be-tracked target isto pass, and the second camera can be an (N+1)-th camera, or can also bean (N+2)-th camera, an (N+3)-th camera, and the like by which theto-be-tracked target is to passes. Embodiments are not limited in thisaspect.

In one case, the first camera can determine a moving speed and a movingdirection of the to-be-tracked target based on the GPS coordinates ofthe to-be-tracked target obtained during the tracking; and predict thecamera by which the to-be-tracked target is to pass as a second camerabased on the moving speed and the moving direction.

For example, the system according to the embodiment of the presentapplication can comprise a plurality of cameras, and these camerasobtain the positions of the other cameras in advance, so that the firstcamera can predict a camera by which the to-be-tracked target is to passbased on the moving speed and the moving direction of the to-be-trackedtarget.

Alternatively, in another case, the first camera can predict a camera bywhich the to-be-tracked target is to pass as the second camera based onthe current road condition and the moving speed of the to-be-trackedtarget.

For example, the to-be-tracked target is a vehicle traveling on a roadwithout a branch. The camera by which the vehicle is to pass can bepredicted only based on the moving speed of the vehicle and thedirection of the road.

In one implementation, the first camera can send the continuouslyobtained GPS coordinates of the to-be-tracked target to the secondcamera after predicting the second camera and before the to-be-trackedtarget moving out of the monitoring range of the first camera.

For example, assuming that the first camera predicts the second cameraat time X, the to-be-tracked target moves out of the monitoring range ofthe first camera at time Y, and the first camera obtains the GPScoordinates of the to-be-tracked target once per second during thetracking of the to-be-tracked target. In this case, the first camera cansend the GPS coordinate to the second camera every time the GPScoordinates of the to-be-tracked target are acquired during the timeperiod from X to Y.

If the system further comprises a server, as another implementation, thefirst camera can send the GPS coordinates of the to-be-tracked targetobtained during the tracking of the to-be-tracked target by the firstcamera to the server. The server predicts a camera by which theto-be-tracked target is to pass as a second camera based on the GPScoordinates of the to-be-tracked target; and sends the GPS coordinatesof the to-be-tracked target to the second camera.

The process of predicting the second camera by the server is similar tothe process of predicting the second camera by the first camera, and isnot described again. The server can send the received GPS coordinate ofthe to-be-tracked target sent by the first camera to the second cameraafter having predicted the second camera.

In one case, the second camera can be a dome camera, and the secondcamera can determine PT coordinates of the second camera at the time ofshooting the to-be-tracked target according to received GPS coordinatesof the to-be-tracked target; and adjust the shooting angle of the camerabased on the PT coordinates.

There are various ways to convert GPS coordinates into PT coordinates,and a new conversion method is proposed in the embodiment of the presentapplication, comprising:

calculating a longitudinal distance and a latitudinal distance betweenthe dome camera and the to-be-tracked target according to the GPScoordinates of the to-be-tracked target and the GPS coordinates of thedome camera; calculating a horizontal distance between the to-be-trackedtarget and the dome camera according to the longitudinal distance andlatitudinal distance; calculating a horizontal angle between theto-be-tracked target and a specified direction through trigonometricfunctions according to the longitudinal distance and latitudinaldistance; determining the P coordinate of the dome camera according tothe horizontal angle; and calculating the T coordinate of the domecamera according to the horizontal distance and the height of the domecamera.

The horizontal distance is the distance between the dome camera and theto-be-tracked target if they are on the same height. Referring to FIG.4, if the ground is considered to be flat, the horizontal distancebetween the to-be-tracked target and the dome camera is calculated byusing formula 1:

${{Horizontal}\mspace{14mu}{distance}} = \sqrt{{{Longitudinal}{\mspace{11mu}\;}{distance}^{2}} + {{Latitudinal}\mspace{14mu}{distance}^{2}}}$

Alternatively, Haversine function can be used to calculate thehorizontal distance between the to-be-tracked target and the dome camerain the following formula:

$L = {2 \times R \times {\arcsin( \sqrt{{\sin^{2}( \frac{{Bw} - {Aw}}{2} )} + {{\cos({Aw})} \times {\cos({Bw})} \times {\sin^{2}( \frac{{Bj} - {Aj}}{2} )}}} )}}$

In this formula, Aw represents the latitude of the to-be-tracked target,Aj represents the longitude of the to-be-tracked target, Bw representsthe latitude of the dome camera, Bj represents the longitude of the domecamera, L represents the horizontal distance between the to-be-trackedtarget and the dome camera, and R represents the radius of the earthwhere the dome camera is located.

Alternatively, the ground is considered to be spherical, and thehorizontal distance between the to-be-tracked target and the domecamera, that is, the spherical surface distance, is calculated by usinga spherical sine and cosine formula. There are various ways to calculatethe horizontal distance between the to-be-tracked target and the domecamera, which will not be listed here.

For example, if the specified direction is north, the ratio of thelongitudinal distance to the latitudinal distance can be calculated asthe tangent of the horizontal angle. The horizontal angle can becalculated through the tangent of the horizontal angle. Referring toFIG. 4, tan θ=the longitudinal distance/the latitudinal distance, and θrepresents a horizontal angle between the to-be-tracked target and thenorth direction.

Alternatively, the specified direction can also be east, in which case,the ratio of the the longitudinal distance to the latitudinal distancecan be calculated as the tangent of the horizontal angle; and thehorizontal angle is calculated through the tangent of the horizontalangle. Referring to FIG. 4, tan α=the latitudinal distance/thelongitudinal distance, and α is a horizontal angle between theto-be-tracked target and the true east direction.

Alternatively, the specified direction can also be west or south, andthe specific calculation process is similar to the above and will not berepeated.

The P coordinate of the dome camera can be understood as the angle ofthe dome camera in the horizontal direction. If the horizontal anglebetween the dome camera and the specified direction is known, the angleof the dome camera in the horizontal direction can be determined, sothat the P coordinate of the dome camera is obtained. The specifieddirection can be north, etc.

In the conversion method, the ratio of the horizontal distance to theheight of the dome camera can be calculated as the tangent of the Tcoordinate of the dome camera; and the T coordinate of the dome cameracan be determined through the tangent of the T coordinate of the domecamera.

Referring to FIG. 3, tan T*h=L, h represents the height of the domecamera, L represents the horizontal distance between the to-be-trackedtarget and the dome camera, and T represents the T coordinate of thedome camera. The T coordinate of the dome camera can be calculatedaccording to the formula.

Based on the above steps, the second camera can convert the GPScoordinates of the to-be-tracked target into PT coordinates of the domecamera, and adjust the shooting angle of the second camera based on thePT coordinate, so that the second camera can track the targetimmediately after the to-be-tracked target enters the shooting range ofthe second camera.

In one implementation, the GPS-based target tracking system furthercomprises a third camera. The second camera obtains the GPS coordinatesof the to-be-tracked target during the tracking of the to-be-trackedtarget, and sends the GPS coordinates of the to-be-tracked target to thethird camera.

As described above, a camera that tracks the target first is referred toas a first camera, and a camera that tracks the target later is referredto as a second camera. In this implementation, after the to-be-trackedtarget moves out of the monitoring range of the first camera, the secondcamera can be used as a new first camera, and a third camera can be usedas a new second camera, and so on. In this way, new cameras arecontinuously employed to track the to-be-tracked target until no furthercamera capable of target tracking is available. Thus, the tracking rangeof the target is greatly improved.

In the above implementation, the first camera sends the GPS coordinatesof the to-be-tracked target to the server, and the server predicts thesecond camera and sends the GPS coordinates of the to-be-tracked targetto the second camera. In this case, the second camera can further sendobtained GPS coordinates of the to-be-tracked target to the server, andthe server can continue to predict a further camera by which theto-be-tracked target is to pass next as a third camera, and send the GPScoordinates of the to-be-tracked target received from the second camerato the third camera.

The third camera continues to track the to-be-tracked target. In otherwords, the third camera can adjust the shooting angle according toreceived GPS coordinates of the to-be-tracked target, and track theto-be-tracked target after detecting the to-be-tracked target in themonitoring image shot by the third camera. This process is similar tothe process of tracking the to-be-tracked target by the second camera,and is thus not repeated again.

In one implementation, there can be multiple third cameras. A firstthird camera adjusts a shooting angle according to received GPScoordinates of the to-be-tracked target, tracks the to-be-tracked targetafter detecting the to-be-tracked target in a monitoring image shot bythe first third camera, obtains GPS coordinates of the to-be-trackedtarget during the tracking of the to-be-tracked target, and sends theGPS coordinates of the to-be-tracked target to the next third camera.

A further third camera receives the GPS coordinates from the last thirdcamera, adjusts the shooting angle, and tracks the to-be-tracked targetafter detecting the to-be-tracked target in a monitoring image shot bythe further third camera, until the tracking is finished.

In another implementation, there can be multiple third cameras. A firstthird camera adjusts a shooting angle according to received GPScoordinates of the to-be-tracked target, tracks the to-be-tracked targetafter detecting the to-be-tracked target in the monitoring image shot bythe first third camera, obtains the GPS coordinates of the to-be-trackedtarget during the tracking of the to-be-tracked target, and sends theGPS coordinates of the to-be-tracked target to the server.

The server sends GPS coordinates of the to-be-tracked target to the nextthird camera. A further third camera receives the GPS coordinates fromthe server, adjusts a shooting angle, and tracks the to-be-trackedtarget after detecting the to-be-tracked target in the monitoring imageshot by the further third camera, until the tracking is finished. Thefurther third camera is a third camera other than the first thirdcamera.

In the system according to the embodiment of the application, the firstcamera obtains GPS coordinates of the target during the tracking of thetarget and sends the GPS coordinates to the second camera; and thesecond camera adjusts the shooting angle of the second camera accordingto the GPS coordinates, and tracks the target after detecting it in thesecond monitoring image shot by the second camera. Therefore, in thesolution, once the target moves out of the monitoring range of the firstcamera, the second camera continues to track the target. In this way,the tracking range of the target is expanded through linkage of theplurality of cameras.

Corresponding to the above embodiment of system, the embodiment of theapplication also provides a GPS-based target tracking method, which canbe applied to a camera, such as a dome camera, or other electronicdevices that are communicatively connected with the camera, such as aserver, and the like. The embodiment is not specifically limited in thisaspect. In the following description, the method is executed on a firstcamera, which can be any camera.

FIG. 5 is a schematic flowchart of a GPS-based target tracking methodaccording to an embodiment of the present application, the methodcomprises:

S501, determining a to-be-tracked target in a first monitoring imageshot by a first camera.

For ease of description, the monitoring image shot by the first camerais referred to as a first monitoring image, and the first camera can bea dome camera.

In one case, the first camera can determine the to-be-tracked target inthe first monitoring image shot by the first camera according to a userinstruction. For example, the first camera can present the firstmonitoring image shot by the first camera to the user, and the userclicks to select the to-be-tracked target in the first monitoring image.As another example, the to-be-tracked target is a vehicle. The user caninput a license plate number of the to-be-tracked target, the firstcamera detects whether the license plate number exists in the firstmonitoring image shot by the first camera. If the license plate numberexists, the vehicle corresponding to the license plate number is takenas the to-be-tracked target.

In another case, S501 can comprise: receiving attribute information ofthe to-be-tracked target sent by a server or a camera other than thefirst camera; and determining the to-be-tracked target in the firstmonitoring image based on the attribute information;

For example, if the to-be-tracked target is a vehicle, the attributeinformation can be a license plate number; if the to-be-tracked targetis a person, the attribute information can be a face feature or aclothing feature.

For example, the server can extract the attribute information of theto-be-tracked target, and sends the attribute information to a camera.The camera then continues to send the attribute information to the nextcamera for tracking the to-be-tracked target. The next camera thencontinues to send the attribute information to the further next camerafor tracking the to-be-tracked target, and so on. Further details areomitted. In this way, each camera can receive the attribute informationsent by the server or another camera, and detect the to-be-trackedtarget in the monitoring image shot by each camera based on the receivedattribute information.

Alternatively, the server can predict a camera by which theto-be-tracked target is to pass based on a historical trajectory of theto-be-tracked target acquired in advance; sending the attributeinformation of the to-be-tracked target to the predicted camera.Alternatively, the server can also send the attribute information of theto-be-tracked target to all cameras or a specified camera managed by theserver.

For example, the first camera can identify each candidate target in thefirst monitoring image and extract attribute information of eachcandidate target; and matching the attribute information of eachcandidate target with the received attribute information, anddetermining the candidate target as the to-be-tracked target if amatching degree is greater than a first preset threshold.

S502, controlling the first camera to track the to-be-tracked target,and to obtain GPS coordinates of the to-be-tracked target during thetracking.

In one case, the first camera can continuously obtain GPS coordinates ofthe to-be-tracked target during the tracking of the to-be-trackedtarget. For example, the GPS coordinate of the to-be-tracked target canbe obtained every second or every millisecond. The specific timeinterval is not limited.

There are various ways to obtain GPS coordinates of the to-be-trackedtarget during the tracking. In one implementation, image coordinates ofthe to-be-tracked target in the first monitoring image may be obtainedduring the tracking; and the image coordinates may be converted into theGPS coordinates of the to-be-tracked target.

For example, the mapping relationship between the image coordinatesystem and the GPS coordinate system can be pre-established, and theimage coordinates of the to-be-tracked target are converted into the GPScoordinates according to the mapping relationship.

In another implementation, PT coordinates of the first camera at thetime of shooting the to-be-tracked target during the tracking areobtained, and are then converted into GPS coordinates of theto-be-tracked target.

There are various ways to convert PT coordinates into GPS coordinates,and a new conversion method is proposed in the embodiment of the presentapplication.

The conversion method can comprise: obtaining the PT coordinates of thefirst camera at the time of capturing the to-be-tracked target, andtaking the P coordinates of the PT coordinate as a first P coordinateand taking the T coordinate of the PT coordinates as a first Tcoordinate; determining a horizontal angle between the to-be-trackedtarget and a specified direction based on the first P coordinate;calculating a horizontal distance between the to-be-tracked target andthe first camera based on the first T coordinate and the height of thefirst camera; calculating, according to the horizontal angle and thehorizontal distance, a longitudinal distance and a latitudinal distancebetween the to-be-tracked target and the first camera throughtrigonometric functions; and calculating the GPS coordinates of theto-be-tracked target based on the longitude and latitude of the firstcamera, and the longitudinal distance and latitudinal distance.

For ease of description, in the conversion method, the first camera isreferred to as a dome camera. The specified direction can be north,south, east, or west, and is not limited specifically.

In the conversion method, the product of the tangent of the first Tcoordinate and the height of the dome camera can be calculated as thehorizontal distance between the to-be-tracked target and the domecamera. Referring to FIG. 3, tan T*h=L, h is the height of the domecamera, and L is the horizontal distance between the to-be-trackedtarget and the dome camera. The horizontal distance is the distancebetween the dome camera and the to-be-tracked target under the conditionthat the heights of the dome camera and the to-be-tracked target are thesame.

If the specified direction is north, the product of the sine of thehorizontal angle and the horizontal distance is calculated and taken asthe longitudinal distance between the to-be-tracked target and the domecamera; and the product of the cosine of the horizontal angle and thehorizontal distance is calculated and taken as the latitudinal distancebetween the to-be-tracked target and the dome camera.

Referring to FIG. 4, FIG. 4 is a top view of the dome camera, and doesnot show the height of the dome camera. As can be seen from FIG. 4,L*sin θ=L_(lon), L*cos θ=L_(lat), L is the horizontal distance obtainedby the above calculation, θ is the horizontal angle between theto-be-tracked target and the north direction, L_(lon) is thelongitudinal distance between the to-be-tracked target and the domecamera, and L_(lat) is the latitudinal distance between theto-be-tracked target and the dome camera.

If the specified direction is east, the product of the cosine of thehorizontal angle and the horizontal distance is calculated and taken asthe longitudinal distance between the to-be-tracked target and the domecamera; and the product of the sine of the horizontal angle and thehorizontal distance is calculated and taken as the latitudinal distancebetween the to-be-tracked target and the dome camera.

In this case, the horizontal angle between the to-be-tracked target andthe east direction is α in FIG. 4, L*sin α=L_(lon), L*cos α=L_(lat).

Alternatively, the specified direction is west or south, and thespecific calculation process is similar and is not described again.

The dome camera is usually provided with a GPS positioning devicethrough which GPS coordinates of the dome camera can be obtained. TheGPS coordinate comprises a longitude and a latitude. With the longitudeand latitude of the dome camera, and longitudinal and latitudinaldistances between the dome camera and the to-be-tracked target, thelongitude and latitude of the to-be-tracked target can be calculated,and the GPS coordinates of the to-be-tracked target is also obtained.

S503, predicting a camera by which the to-be-tracked target is to passbased on the GPS coordinates of the to-be-tracked target obtained duringthe tracking, and taking the predicted camera as a second camera

The camera by which the to-be-tracked target is to pass can be a nextcamera by which the to-be-tracked target is to pass. It is assumed thatthe first camera is an N-th camera by which the to-be-tracked target isto pass, and the second camera can be an (N+1)-th camera, or can also bean (N+2)-th camera, an (N+3)-th camera, and the like by which theto-be-tracked target is to passes. Embodiments are not limited in thisaspect.

In one case, the first camera can determine a moving speed and a movingdirection of the to-be-tracked target based on the GPS coordinates ofthe to-be-tracked target obtained during the tracking; and predict thecamera by which the to-be-tracked target is to pass as a second camerabased on the moving speed and the moving direction.

For example, the first camera may obtain positions of the other camerasin advance, so that the first camera can predict a camera by which theto-be-tracked target is to pass based on the moving speed and the movingdirection of the to-be-tracked target.

Alternatively, in another case, the first camera can predict a camera bywhich the to-be-tracked target is to pass as the second camera based onthe current road condition and the moving speed of the to-be-trackedtarget.

For example, the to-be-tracked target is a vehicle traveling on a roadwithout a branch. The camera by which the vehicle is to pass can bepredicted only based on the moving speed of the vehicle and thedirection of the road.

S504, sending the GPS coordinates of the to-be-tracked target to thesecond camera so that the second camera tracks the to-be-tracked targetaccording to the GPS coordinates of the to-be-tracked target.

In one implementation, the first camera can send the continuouslyobtained GPS coordinates of the to-be-tracked target to the secondcamera after predicting the second camera and before the to-be-trackedtarget moving out of the monitoring range of the first camera.

For example, assuming that the first camera predicts the second cameraat time X, the to-be-tracked target moves out of the monitoring range ofthe first camera at time Y, and the first camera obtains the GPScoordinates of the to-be-tracked target once per second during thetracking of the to-be-tracked target. In this case, the first camera cansend the GPS coordinate to the second camera every time the GPScoordinates of the to-be-tracked target are acquired during the timeperiod from X to Y.

As described above, for each camera, it can receive the attributeinformation sent by the server or other cameras, and detect theto-be-tracked target in the monitoring image shot by each camera basedon the received attribute information. In one case, after S503, thefirst camera can send the attribute information of the to-be-trackedtarget to the second camera. The second camera can adjust the shootingangle of the second camera according to the received GPS coordinate ofthe to-be-tracked target, and tracks the to-be-tracked target afterdetecting the to-be-tracked target in the second monitoring image shotby the second camera according to the attribute information.

after receiving the GPS coordinate of the to-be-tracked target sent bythe server or a camera other than the second camera, the second cameradetermines a PT coordinate of the second camera when shooting theto-be-tracked target according to the received GPS coordinate of theto-be-tracked target; and adjusting the shooting angle of the secondcamera based on the PT coordinate.

There are various ways to convert GPS coordinates into PT coordinates,and a new conversion method is proposed in the embodiment of the presentapplication, comprising:

calculating a longitudinal distance and a latitudinal distance betweenthe dome camera and the to-be-tracked target according to the GPScoordinates of the to-be-tracked target and the GPS coordinates of thedome camera; calculating a horizontal distance between the to-be-trackedtarget and the dome camera according to the longitudinal distance andlatitudinal distance; calculating a horizontal angle between theto-be-tracked target and a specified direction through trigonometricfunctions according to the longitudinal distance and latitudinaldistance; determining the P coordinate of the dome camera according tothe horizontal angle; and calculating the T coordinate of the domecamera according to the horizontal distance and the height of the domecamera.

The horizontal distance is the distance between the dome camera and theto-be-tracked target if they are on the same height. Referring to FIG.4, if the ground is considered to be flat, the horizontal distancebetween the to-be-tracked target and the dome camera is calculated byusing formula 1:

${{Horizontal}\mspace{14mu}{distance}} = \sqrt{{{Longitudinal}{\mspace{11mu}\;}{distance}^{2}} + {{Latitudinal}\mspace{14mu}{distance}^{2}}}$

Alternatively, Haversine function can be used to calculate thehorizontal distance between the to-be-tracked target and the dome camerain the following formula:

$L = {2 \times R \times {\arcsin( \sqrt{{\sin^{2}( \frac{{Bw} - {Aw}}{2} )} + {{\cos({Aw})} \times {\cos({Bw})} \times {\sin^{2}( \frac{{Bj} - {Aj}}{2} )}}} )}}$

In this formula, Aw represents the latitude of the to-be-tracked target,Aj represents the longitude of the to-be-tracked target, Bw representsthe latitude of the dome camera, Bj represents the longitude of the domecamera, L represents the horizontal distance between the to-be-trackedtarget and the dome camera, and R represents the radius of the earthwhere the dome camera is located.

Alternatively, the ground is considered to be spherical, and thehorizontal distance between the to-be-tracked target and the domecamera, that is, the spherical surface distance, is calculated by usinga spherical sine and cosine formula. There are various ways to calculatethe horizontal distance between the to-be-tracked target and the domecamera, which will not be listed here.

For example, if the specified direction is north, the ratio of thelongitudinal distance to the latitudinal distance can be calculated asthe tangent of the horizontal angle. The horizontal angle can becalculated through the tangent of the horizontal angle. Referring toFIG. 4, tan θ=the longitudinal distance/the latitudinal distance, and θrepresents a horizontal angle between the to-be-tracked target and thenorth direction.

Alternatively, the specified direction can also be east, in which case,the ratio of the the longitudinal distance to the latitudinal distancecan be calculated as the tangent of the horizontal angle; and thehorizontal angle is calculated through the tangent of the horizontalangle. Referring to FIG. 4, tan α=the latitudinal distance/thelongitudinal distance, and α is a horizontal angle between theto-be-tracked target and the true east direction.

Alternatively, the specified direction can also be west or south, andthe specific calculation process is similar to the above and will not berepeated.

The P coordinate of the dome camera can be understood as the angle ofthe dome camera in the horizontal direction. If the horizontal anglebetween the dome camera and the specified direction is known, the angleof the dome camera in the horizontal direction can be determined, sothat the P coordinate of the dome camera is obtained. The specifieddirection can be true north, etc.

In the conversion method, the ratio of the horizontal distance to theheight of the dome camera can be calculated as the tangent of the Tcoordinate of the dome camera; and the T coordinate of the dome cameracan be determined through the tangent of the T coordinate of the domecamera.

Referring to FIG. 3, tan T*h=L, h represents the height of the domecamera, L represents the horizontal distance between the to-be-trackedtarget and the dome camera, and T represents the T coordinate of thedome camera. The T coordinate of the dome camera can be calculatedaccording to the formula.

In the embodiment of the present application, the first camera obtainsthe GPS coordinates of the target during the tracking of the target andsends the GPS coordinates to the second camera; and the second cameraadjusts the shooting angle of the second camera according to the GPScoordinates, and tracks the target after detecting the target in asecond monitoring image shot by the second camera. Therefore, in thesolution, if the target moves out of the monitoring range of the firstcamera, the second camera continues to track the target. As such, thetracking range of the target is expanded through linkage of theplurality of cameras.

An embodiment of the present application also provides a dome camera,which comprises an image acquirer 601, a processor 602 and a memory 603.

The image acquirer 601 is configured for shooting monitoring images.

The memory 602 is configured for storing a computer program.

The processor 603 is configured for implementing any one of theabove-mentioned GPS-based target tracking methods when executing theprogram stored in the memory 602.

In the embodiment of the present application, the first camera obtainsthe GPS coordinates of the target during the tracking of the target andsends the GPS coordinates to the second camera; and the second cameraadjusts the shooting angle of the second camera according to the GPScoordinates, and tracks the target after detecting the target in asecond monitoring image shot by the second camera. Therefore, in thesolution, if the target moves out of the monitoring range of the firstcamera, the second camera continues to track the target. As such, thetracking range of the target is expanded through linkage of theplurality of cameras.

The image acquirer can comprise various components such as a lens and animage sensor, which are not limited specifically.

The Memory can comprise a Random Access Memory (RAM) or a Non-VolatileMemory (NVM), such as at least one disk memory. In one embodiment, thememory can also be at least one memory device located remotely from theprocessor.

The Processor can be a general-purpose processor, comprising a CentralProcessing Unit (CPU), a Network Processor (NP), and the like; but alsoa Digital Signal Processor (DSP), an Application Specific IntegratedCircuits (ASIC), a Field Programmable Gate Arrays (FPGA) or otherprogrammable logic devices, discrete Gate or transistor logic devices,discrete hardware components.

It should be noted that, in this document, relational terms such asfirst and second, and the like are used only to distinguish one entityor action from another entity or action without necessarily requiring orimplying any actual such relationship or order between such entities oractions. Also, the terms “comprises,” “comprising,” or any othervariation thereof, are intended to cover a non-exclusive inclusion, suchthat a process, method, article, or device that comprises a list ofelements does not comprise only those elements but can comprise otherelements not expressly listed or inherent to such process, method,article, or device. Without further limitation, an element defined bythe phrase “ comprising an . . .” does not exclude the presence of otheridentical elements in the process, method, article, or apparatus thatcomprises the element.

All embodiments in the present description are described in a relatedmanner, and the same and similar parts among the embodiments can bereferred to each other, and each embodiment focuses on differences fromother embodiments. In particular, method embodiment and dome cameraembodiment are described in relative terms that are substantiallysimilar to system embodiment, and the relevant parts can be referred tothe part of the description of the system embodiment.

The above description are only preferred embodiments of the presentapplication and should not be taken as limiting the present application,and any modifications, equivalents, improvements and the like madewithin the spirit and principle of the present application should beincluded in the protection scope of the present application.

1. A GPS-based target tracking system, comprising: a first camera and asecond camera; the first camera is configured for determining ato-be-tracked target in a first monitoring image shot by the firstcamera, tracking the to-be-tracked target, obtaining GPS coordinates ofthe to-be-tracked target during the tracking, and sending the GPScoordinates of the to-be-tracked target to the second camera; and thesecond camera is configured for adjusting a shooting angle according toreceived GPS coordinates of the to-be-tracked target, and tracking theto-be-tracked target after detecting the to-be-tracked target in asecond monitoring image shot by the second camera.
 2. The systemaccording to claim 1, wherein, the first camera is further configuredfor: converting image coordinates of the to-be-tracked target in thefirst monitoring image into the GPS coordinates of the to-be-trackedtarget; or converting PT coordinates for the first camera to capture theto-be-tracked target into the GPS coordinates of the to-be-trackedtarget.
 3. The system according to claim 2, wherein, the first camera isfurther configured for: obtaining the PT coordinates to capture theto-be-tracked target, and taking the P coordinate of the PT coordinatesas a first P coordinate and taking the T coordinate of the PTcoordinates as a first T coordinate; determining a horizontal anglebetween the to-be-tracked target and a specified direction based on thefirst P coordinate; calculating a horizontal distance between theto-be-tracked target and the first camera based on the first Tcoordinate and the height of the first camera; calculating, according tothe horizontal angle and the horizontal distance, a longitudinaldistance and a latitudinal distance between the to-be-tracked target andthe first camera through trigonometric functions; and calculating theGPS coordinates of the to-be-tracked target based on the longitude andlatitude of the first camera, and the longitudinal distance andlatitudinal distance.
 4. The system according to claim 1, wherein, thefirst camera is further configured for: predicting a camera by which theto-be-tracked target is to pass based on the GPS coordinates of theto-be-tracked target obtained during the tracking, and taking thepredicted camera as the second camera; and sending the GPS coordinatesof the to-be-tracked target to the second camera.
 5. The systemaccording to claim 1, wherein, the second camera is a dome cameraconfigured for: determining PT coordinates for the dome camera tocapture the to-be-tracked target according to received GPS coordinatesof the to-be-tracked target; and adjusting a shooting angle of the domecamera based on the PT coordinates.
 6. The system according to claim 5,wherein the dome camera is further configured for: calculating alongitudinal distance and a latitudinal distance between the dome cameraand the to-be-tracked target according to the GPS coordinates of theto-be-tracked target and the GPS coordinates of the dome camera;calculating a horizontal distance between the to-be-tracked target andthe dome camera according to the longitudinal distance and latitudinaldistance; calculating a horizontal angle between the to-be-trackedtarget and a specified direction through trigonometric functionsaccording to the longitudinal distance and latitudinal distance;determining the P coordinate of the dome camera according to thehorizontal angle; and calculating the T coordinates of the dome cameraaccording to the horizontal distance and the height of the dome camera.7. The system according to claim 1, further comprising: a server,configured for sending attribute information of the to-be-tracked targetto the first camera; the first camera is configured for determining,based on received attribute information, the to-be-tracked target in thefirst monitoring image shot by the first camera; and sending theattribute information to the second camera; and the second camera isconfigured for detecting, based on the received attribute information,the to-be-tracked target in the second monitoring image shot by thesecond camera.
 8. The system according to claim 7, wherein the server isfurther configured for: predicting a camera by which the to-be-trackedtarget is to pass based on a pre-acquired historical trajectory of theto-be-tracked target; sending the attribute information of theto-be-tracked target to the predicted camera; or sending the attributeinformation of the to-be-tracked target to cameras managed by theserver; or sending the attribute information of the to-be-tracked targetto a specified camera managed by the server; wherein, each of thepredicted camera, the cameras, and the specified camera comprises thefirst camera.
 9. The system according to claim 7, wherein the firstcamera is further configured for: sending the GPS coordinates of theto-be-tracked target obtained during the tracking of the to-be-trackedtarget to the server; and the server is further configured for:predicting a camera by which the to-be-tracked target is to pass basedon the GPS coordinates of the to-be-tracked target and taking thepredicted camera as the second camera; and sending the GPS coordinatesof the to-be-tracked target to the second camera.
 10. The systemaccording to claim 1, further comprising: a third camera; the secondcamera is further configured for obtaining GPS coordinates of theto-be-tracked target during the tracking of the to-be-tracked target,and sending the GPS coordinates of the to-be-tracked target to the thirdcamera; the third camera is configured for adjusting a shooting angleaccording to received GPS coordinates of the to-be-tracked target, andtracking the to-be-tracked target after detecting the to-be-trackedtarget in a monitoring image shot by the third camera.
 11. A GPS-basedtarget tracking method, comprising: determining a to-be-tracked targetin a first monitoring image shot by a first camera; controlling thefirst camera to track the to-be-tracked target, and to obtain GPScoordinates of the to-be-tracked target during the tracking; predictinga camera by which the to-be-tracked target is to pass based on the GPScoordinates of the to-be-tracked target obtained during the tracking,and taking the predicted camera as a second camera; and sending the GPScoordinates of the to-be-tracked target to the second camera so that thesecond camera tracks the to-be-tracked target according to the GPScoordinates of the to-be-tracked target.
 12. The method according toclaim 11, wherein determining a to-be-tracked target in a firstmonitoring image shot by a first camera comprises: receiving attributeinformation of the to-be-tracked target sent by a server or a cameraother than the first camera; and determining the to-be-tracked target inthe first monitoring image based on the attribute information; afterpredicting a camera by which the to-be-tracked target is to pass basedon the GPS coordinates of the to-be-tracked target obtained during thetracking, and taking the predicted camera as a second camera; the methodfurther comprises: sending the attribute information to the secondcamera so that the second camera detects, based on the receivedattribute information, the to-be-tracked target in a second monitoringimage shot by the second camera.
 13. The method according to claim 11,wherein obtaining GPS coordinates of the to-be-tracked target during thetracking comprises: obtaining image coordinates of the to-be-trackedtarget in the first monitoring image during the tracking; converting theimage coordinates into the GPS coordinates of the to-be-tracked target;or obtaining PT coordinates for the first camera to capture theto-be-tracked target during the tracking, and converting the PTcoordinates into the GPS coordinates of the to-be-tracked target. 14.The method according to claim 13, wherein converting the PT coordinatesinto the GPS coordinates of the to-be-tracked target comprises:obtaining the PT coordinates for the first camera to capture theto-be-tracked target, and taking the P coordinates of the PT coordinateas a first P coordinate and taking the T coordinate of the PTcoordinates as a first T coordinate; determining a horizontal anglebetween the to-be-tracked target and a specified direction based on thefirst P coordinate; calculating a horizontal distance between theto-be-tracked target and the first camera based on the first Tcoordinate and the height of the first camera; calculating, according tothe horizontal angle and the horizontal distance, a longitudinaldistance and a latitudinal distance between the to-be-tracked target andthe first camera through trigonometric functions; and calculating theGPS coordinates of the to-be-tracked target based on the longitude andlatitude of the first camera, and the longitudinal distance andlatitudinal distance.
 15. The method according to claim 11, whereincontrolling the first camera to track the to-be-tracked targetcomprises: receiving attribute information of the to-be-tracked targetsent by a server or a camera other than the first camera; determining PTcoordinates for the first camera to capture the to-be-tracked targetaccording to received GPS coordinates of the to-be-tracked target; andadjusting a shooting angle of the first camera based on the PTcoordinates.
 16. The method according to claim 15, wherein determiningPT coordinates for the first camera to capture the to-be-tracked targetaccording to received GPS coordinates of the to-be-tracked targetcomprises: calculating a longitudinal distance and a latitudinaldistance between the first camera and the to-be-tracked target accordingto the GPS coordinates of the to-be-tracked target and GPS coordinatesof the first camera that captures the to-be-tracked target; calculatinga horizontal distance between the to-be-tracked target and the firstcamera according to the longitudinal distance and latitudinal distance;calculating a horizontal angle between the to-be-tracked target and aspecified direction through trigonometric functions according to thelongitudinal distance and latitudinal distance; determining the Pcoordinate of the first camera according to the horizontal angle; andcalculating the T coordinate of the first camera according to thehorizontal distance and the height of the first camera.
 17. A domecamera, comprising: an image acquirer configured for shooting monitoringimages; a memory configured for storing a computer program; and aprocessor configured for implementing the method steps of claim 11 whenexecuting the program stored in the memory.